Immune Response and Currently Used Immunizing Agents under UNIVERSAL IMMUNIZATION PROGRAMME

PRESENTED BY:- DR.NAVIN KUMAR

What is immunity? Immunity involves the antigen-

antibody responses. From the Latin word “immunis”—

exempt. Immunity involves the antigen-

antibody responses. The immune system produces

antibodies or cells that can deactivate pathogens.

The immune system recognizes, attacks, destroys, and remembers each pathogen that enters the body.

 It does this by making specialized cells and antibodies that render the pathogens harmless.

For each type of pathogen, the immune system produces cells that are specific for that particular pathogen

Functions of the Immune System

Immune System has 3 main functions:– Protect the body from pathogens– Remove dead or damaged tissue and

cells– Recognize and remove abnormal cells

that have abnormal cell growth and development (i.e. cancer cells)

The Immune System - includes all parts of the body that help in the recognition and destruction of foreign materials.

- White blood cells, phagocytes and lymphocytes, bone marrow, lymph nodes, tonsils, thymus, and spleen are all part of the immune system.  

Active immunity Resistance developed in response to

stimulus by an antigen (infecting agent or vaccine) and is characterized by the production of antibodies by the host.

Active Immunity occurs when one makes his/her own antibodies.- This type of immunity is long term.

Getting the disease : If one get an infectious disease (like Chicken Pox), often times, that stimulates the production of MEMORY cells which are then stored to prevent the infection in the future.

A. HUMORAL IMMUNITY

:

This type of immunity is due to circulating Abs

(Gamma-globulin's also called immunoglobulins)

On stimulation, B-lymphocytes divide and its

daughter cells are transformed into plasma-

cells.

The latter secrete the Abs into the circulation. An antibody is a protein produced in

response to an antigen.

5 Types of Antibodies Immunoglobulin G (IgG)—in plasma

and tissue fluids; effective against virus, bacteria, & toxins; activate complement; babies get from mother through cord lasts 6 months to 1 yr

Immunoglobulin A (IgA)—in exocrine gland secretions (sweat glands); breast milk, tears, nasal fluid, bile, urine, etc.

Immunoglobulin M (IgM)—develops in response to bacteria

Immunoglobulin D (IgD)—found on surfaces of B-cells; important to B-cell activation

Immunoglobulin E (IgE)—in exocrine secretions along with IgA; ASSOCIATED WITH ALLERGIC REACTIONS

B. CELLULAR IMMUNITY

Another way of establishing host resistance is through

T-lymphocytes.

These cells synthesize and release pharmacologically

active substances ("lymphokines") which can kill

cell carrying foreign Ags.

T-lymphocytes also act against the invader by stimulation of macrophages.

This activity of the immune system is known as cell mediated immunity. The peak of activity occurs around the tenth day.

CELL MEDIATED IMMUNITY

In cell mediated immunity, the t-cells attach to foreign antigen cells and interact directly by cell to cell contact

PASSIVE IMMUNITY

Immunity conferred by an antibody produced in another host.

It may be acquired naturally or artificially (through an antibody-containing preparation).

PASSIVE IMMUNITY While our immune system was developing,

We were protected by immune defenses called antibodies.

These antibodies traveled across the placenta from the maternal blood to the fetal

blood.

Passive Immunity occurs when the antibodies come from some other source. This type of immunity is of short term.

Breastmilk : Milk from a mother's

breast contains antibodies.

The baby is acquiring passive immunity.

These antibodies will only last several weeks.

IMMUNIZING AGENTS

IMMUNIZING AGENTS

ANTISERAIMMUNOGLOBULINSVACCINES

IMMUNIZING AGENTS

Vaccine: Vaccine is an immuno-biological substance designed to produce specific protection against a given disease.

Toxoid: Exotoxins produced by some bacteria are detoxified and used in the preparation of vaccine.

Immuno globulin: sterile solution containing antibodies from human blood.

Antitoxin: solution of antibodies derived from the serum of non-human sources.

Vaccination and Immunization

Vaccination and vaccine derived from

vaccinia, the virus once used as smallpox

vaccine.

Thus, vaccination originally meant

inoculation with vaccinia virus to render a

person immune to smallpox.

IMMUNIZATIONS

Immunization: process of inducing or providing immunity by administering an agent

Active: production of an antibody in response to the administration of a vaccine

Passive: temporary immunity by the administration of preformed antibodies or antitoxins

Agents used include: Ig’s and antitoxins

Vaccination: A vaccination is an injection of a weakened form of the actual antigen that causes the disease. -The injection is too weak to make one sick, but his B lymphocytes will recognize the antigen and react as if it were the "real thing". - Thus, he produce MEMORY cells for long term immunity.

Live attenuated (avirulent) vaccines

Virulent pathogenic organisms are treated to become attenuated and avirulent but antigenic.

They have lost their capacity to induce full-blown disease but retain their immunogenicity.

Live attenuated vaccines should not be administered to persons with suppressed immune response due to:– Leukemia and lymphoma AND other malignancies.– Receiving corticosteroids and anti-metabolic agents– Radiation– pregnancy

Inactivated (killed) vaccines

Organisms are killed or inactivated by heat or chemicals but remain antigenic.

They are usually safe but less effective than live attenuated vaccines.

The only absolute contraindication to their administration is a severe local or general reaction to a previous dose.

Polysaccharide and polypeptide (cellular fraction) vaccines

They are prepared from extracted cellular fractions for e.g.

Meningococcal vaccine from the polysaccharide antigen of the cell wall

Pneumococcal vaccine from the polysaccharide contained in the capsule of the organism

Hepatitis B polypeptide vaccine.

Their efficacy and safety appear to be high.

Surface antigen (recombinant) vaccines

• Are those in which genes for desired antigens are inserted into a vector, usually a virus, that has a very low virulence.

• The vector expressing the antigen may be used as the vaccine, or the antigen may be purified and injected as a subunit vaccine.

• The only recombinant vaccine currently in use in humans is the Hepatitis B Virus (HBV) vaccine, which is a recombinant subunit vaccine

• Hepatitis B surface antigen is produced from a gene transfected into yeast cells and purified for injection as a subunit vaccine.

IMMUNE RESPONSE

The specific reactivity induced in a host by an stimulus is known as the immune response.

It has a wider scope and includes reactions against any ANTIGEN, living or non-living.

It may lead to consequences that are beneficial, indifferent or injurious to the HOST.

PRIMARY RESPONSE: When an Ag is administered for the first time to a host (never exposed), there is a latent period of induction of 3-10 days before Ab appears in the blood. Ab- IgM apears 1st , its titre rises

steadily in next 2-3 days, reaches a peak level then declines as fast as it developed.

Meanwhile, if the ANTIGENIC stimulus was sufficient, IgG Ab appears in few days.

Reaches a peak in 7-10 days then gradually falls over a period of weeks or month.

SECONDARY(BOOSTER) RESPONSE

Shorter latent period Production of Ab is more rapid Produces both IgG and IgM Ab more abundant Ab response maintained at higher levels for a

longer period Ab elicited tends to have a greater capacity to

bind to the antigen Collaboration of B-cell and T-cell is essential to

initiate a secondary response.

WHO launched a global immunization programme “EXPANDED PROGRAMME OF IMMUNIZATION” in May,1974 to protect all children against six vaccine-preventable diseases:

DIPHTHERIA, WOOPING COUGH, TETANUS, POLIO, TUBERCULOSIS and MEASLES.

EPI launched in INDIA in January, 1978.

Currently Used Immunizing agents In National Immunization Schedules as UNIVERSAL IMMUNIZATION PROGRAMME in india.

Launched on 19th november.1985 Aimed to achieve Universal

immunization coverage of the eligible population by 1990.

NATIONAL IMMUNIZATION SCHEDULE

FACTSHEET OF OPV IN INDIA

Cases in 2011: 1 (last case 13 January 2011) Cases in 2010: 43 Cases in 2009: 756 Cases in 1991: 5,895 Cases in 1985: 22,570 Last wild poliovirus type 1 (WPV1) case: 13 January 2011, Howrah, West Bengal Last wild poliovirus type 2(WPV2) case: October1999, Aligarh, Uttar Pradesh Last wild poliovirus type 3 (WPV3) case: 22 October 2010, Pakur, Jharkhand

HIB VACCINE

Bacterial Meningitis kills several in Developing world Haemophilus influenzae type b (Hib):

30% -50% of bacterial meningitis

Pneumococcus 25- 35% of bacterial meningitis

Meningococcus

25 - 35% of bacterial meningitis (except during epidemics)

HIB VACCINE Reduces incidence of Hib MENINGITIS,

PNEUMONIA and Nasopharyngeal colonization by Hib bacteria in infants.

Capsular polysaccharide conjugated with protein carrier .

Contraindicated in less than 6 weeks of age.

Vaccine schedule: 6th ,10th and 14th wk. Children over 5 years old usually do not need

Hib vaccine.

HIB VACCINE

INDIA: Tamil Nadu will be the 1st state to vaccinate all Newborns in the state.

PENTAVALENT vaccine: combines with DPT, Hepatitis B and Hib bacteria vaccine.

Hepatitis B vaccine

Is a very safe vaccine Very effective Infants born to HBsAg-positive

mothers should receive the vaccine and HBIG within 12hr of birth.

DTP VACCINE

Inactivated whole organism vaccine DTP or Acellular vaccine DTaP

Acellular type has less side effects

Side effects : Mild Problems (Common): Fever, Redness, swelling, Soreness (1 in 4) Fussiness ,Tiredness or poor appetite

and Vomiting (1 in 50)

BCG VACCINE There is evidence that BCG provides

appreciable protection against tuberculosis meningitis (50-80%) and milliary disease.

Intra-dermal injection. Local lesion, papule, 2 weeks after

vaccination. Small abscess might develop, 4-6

weeks. At 6 weeks (crust, detaches, ulcerates)

then a scar (typically round and slightly depressed) remains.

MMR VACCINE• Live attenuated vaccine• Subcutaneous injection• Side effects : Mild Problems : 1. Mild rash (1 in 20) 2. Swelling of glands in the cheeks

or neck (rare) If these problems occur, it is usually within 7-12 days after the shot.

They occur less often after the second dose

REFERENCES:

PARK’S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE.

TEXTBOOK OF MICROBIOLOGY by Ananthanarayan and Panikar.

MOHFW (GOVT.OF INDIA). WHO vaccine-preventable diseases: monitoring system

2012 global summary. WHO | Poliomyelitis

IMMUNIZATION

THANK YOU

DR.NAVIN KUMARDR.NAVIN KUMAR